ADEN: Five suspected al Qaeda militants were killed in an air strike in eastern Yemen, the Interior Ministry said on Friday, in an escalating campaign against the militant group's Yemeni branch after recent warnings of possible attacks.

The ministry said the men were attacked while they were travelling in a vehicle in the province of Hadramout in an area called Ghail Bawazeer, 45 km from the provincial capital Mukalla.

It did not elaborate on the source of the air strike, but a Yemeni official earlier told Reuters that a US drone fired the missiles.

Residents reported hearing a large explosion and later saw the car destroyed.

“Security authorities in Hadramout are keeping the bodies at a morgue in the hospital while legal proceedings are being finalised,” the ministry said.

Yemen said on Wednesday it had foiled a plot by al Qaeda to seize Mukalla, a port city on the Gulf of Aden, as well as two major oil and gas export terminals.

This announcement came after intelligence on potential attacks by militants prompted Washington to shut missions across the Middle East, and the United States and Britain to evacuate staff from Yemen.

Earlier on Thursday, eight militants died in two drone strikes in the central Yemeni province of Maarib and in Hadramout.

At least 30 al Qaeda suspects have been killed by drones in the past two weeks, a marked increase in the frequency of such strikes.

Yemen is one of a handful of countries where Washington acknowledges using drones, although it does not comment publicly on the practice.

Security in Yemen is of regional and global importance.

As the base for al Qaeda in the Arabian Peninsula (AQAP), considered one of the most aggressive branches of the global militant organisation, Yemen shares a long border with Saudi Arabia, a US ally and the world's top oil exporter.

AQAP has carried out attacks in Saudi Arabia and has made several attempts on US targets. In 2009, Nigerian Umar Farouk Abdulmutallab, who had been trained by AQAP in Yemen, tried to blow up a Detroit-bound airliner with a bomb in his underpants.